Brian, you've probably already looked at your '64.. hope you found a good one and snatched it up. Anyhow, here's some of the nasty suprises I found in the '65 I rescued. Rust in the trunk floor, you can't get the filler panels that go from the trunk floor sides to the bottom edges of the qtr. panels for '64-'65's(yet),typical rust around rear wheelwells, rust in windshield channel(found holes I could stick my thumb through here!), that rusty/leaky windshield channel can(has in my case) extend into the dash under the pad, rust in lower fender area, possibly expensive center link(depending on orig. equip.,I think the 13/16ths units are way more than the 7/8ths). It seems the '64-'65's are sometimes forgotten by the repop folks. I haven't seen any aftermarket door skins, fenders or hoods for our classics yet; same with bumpers, some odd bits of trim are unavailable, as well as consoles and in your case, dash bezels.
On the plus side, the '64-'65's are a little more scarce than the others, you're not gonna get lost in the crowd of '68-'72's when you're cruisin'. Good luck, Bryan